Explosion-proof luminaire

Abstract

The invention relates to an explosion-proof luminaire (1) comprising a luminaire housing (2), at least one light source (3) arranged in the luminaire housing (2), a reflective device (4) assigned to the light source (3) for deflecting light emitted by the light source (3) in the direction of a light exit opening (5) in the luminaire housing (2) and a cooling device (6) assigned to the light source (3) and/or the luminaire housing (2). In particular, an inner side (7) of the luminaire housing (2) is formed, at least pointwise, as a reflective device (4) and/or the cooling device (6) is formed in one piece with the luminaire housing (2).

Claims

1. An explosion-proof lamp comprising: a lamp housing that defines a light outlet opening and comprises an inner side, said inner side of the lamp housing defining a housing interior; at least one light source arranged in said lamp housing; a reflection device associated with said at least one light source for deflecting light emitted by said at least one light source in a direction of said light outlet opening of said lamp housing; a cooling device associated with said lamp housing, wherein said inner side of said lamp housing is formed, at least in some locations, as said reflection device, wherein said cooling device and said reflection device are integral with and formed in one piece with said lamp housing, and wherein said light outlet opening is covered by a cover plate that is translucent or transparent; a cover plate holder that is assigned to said light outlet opening, said cover plate holder coupled to said lamp housing to fasten said cover plate to said lamp housing such that said coupling of said cover plate holder and said cover plate with said lamp housing is compliant with ignition protection class Ex-d, wherein said cover plate holder comprises: a placement flange that defines and adjoins a holder opening, wherein said cover plate is placed on and supported by said placement flange such that at least a portion of said cover plate covers said holder opening, and an insertion flange that protrudes from a lateral end of said placement flange, wherein the insertion flange extends in a direction toward said housing interior and connects to said inner side of said lamp housing when said cover plate holder is coupled to the lamp housing; and a printed circuit board ring having a first surface and a second surface that is opposite to said first surface, wherein said at least one light source is disposed on said first surface of said printed circuit board ring, and wherein when the cover plate holder is coupled to the lamp housing, said printed circuit board ring is clamped between an upper end of said insertion flange and a stepped shoulder formed on said inner side of said lamp housing such that said second surface of said printed circuit board ring engages said upper end of said insertion flange and said first surface of said printed circuit board ring engages said stepped shoulder.

2. The explosion-proof lamp according to claim 1, characterized in that said reflection device is formed as a coating of said inner side.

3. The explosion-proof lamp according to claim 1, characterized in that said lamp housing is formed to be a substantially semi-cylindrical or hemispherical casing, where said reflection device is formed along a curved portion of said casing on said inner side.

4. The explosion-proof lamp according to claim 1, characterized in that said cooling device is formed on an outer side of said lamp housing that is opposite said inner side.

5. The explosion-proof lamp according to claim 1, characterized in that said cooling device comprises a number of cooling fins protruding outwardly from an outer side of said lamp housing that is opposite said inner side.

6. The explosion-proof lamp according to claim 5, characterized in that said cooling fins have a same height and/or length.

7. The explosion-proof lamp according to claim 1, characterized in that openings at oppositely disposed longitudinal ends of said lamp housing are covered by end cover plates that are detachably fastened to said lamp housing.

8. The explosion-proof lamp according to claim 7, characterized in that support flanges protrude on either of said longitudinal ends from an outer side of said lamp housing, through which fastening screws can be passed for detachably fastening said oppositely disposed end cover plates.

9. The explosion-proof lamp according to claim 1, characterized in that said at least one light source is disposed on said inner side of said lamp housing.

10. The explosion-proof lamp according to claim 1, characterized in that a connection between said cover plate and said placement flange is configured in compliance with ignition protection class Ex-d.

11. The explosion-proof lamp according to claim 10, characterized in that the connection between said cover plate and said placement flange is formed by adhesive bonding.

12. The explosion-proof lamp according to claim 1, characterized in that said connection between said insertion flange and said inner side of said lamp housing is formed in compliance with ignition protection class Ex-d.

13. The explosion-proof lamp according to claim 1, characterized in that said insertion flange is formed as a screw-in ring, where a screw connection between said inner side of said lamp housing and an outer side of said screw-in ring is affected by an Ex-d thread.

14. The explosion-proof lamp according to claim 13, characterized in that said printed circuit board ring is mounted on said screw-in ring.

15. The explosion-proof lamp according to claim 13, wherein said screw-in ring is screwed into said lamp housing.

16. The explosion-proof lamp according to claim 1, characterized in that said cooling device is formed by an outer side of said lamp housing.

17. An explosion-proof lamp comprising: a lamp housing that defines a light outlet opening and comprising an inner side and an outer side that is opposite to the inner side, said inner side of the lamp housing defining a housing interior; at least one light source arranged in said lamp housing, wherein said inner side of said lamp housing comprises a bearing flange protruding into said housing interior, and wherein said bearing flange is configured to detachably fasten said at least one light source to the lamp housing; a reflection device defined by the inner side and associated with said at least one light source for deflecting light emitted by said at least one light source in a direction of said light outlet opening of said lamp housing; a cooling device defined by said outer side, wherein said cooling device and said reflective device are integrally formed with said lamp housing such that said reflective device, said cooling device, and said lamp housing are one piece, and a cover plate holder that is separate from said lamp housing and assigned to said light outlet opening, said cover plate holder coupled to said lamp housing to couple a cover plate to said lamp housing such that: (a) said coupling of said cover plate holder and said cover plate with said lamp housing is compliant with ignition protection class Ex-d, and (b) at least a portion of said cover plate covers the light outlet opening, and wherein said cover plate holder comprises a placement flange that defines and adjoins a holder opening, wherein said cover plate is placed on and supported by said placement flange such that at least a portion of said cover plate covers said holder opening, and wherein said cover plate holder comprises an abutment flange facing outwardly from said placement flange and abutting from beneath against said bearing flange while forming a connection that is in compliance with ignition protection class Ex-d.

18. The explosion-proof lamp according to claim 17, wherein said bearing flange extends along said light outlet opening.

19. The explosion-proof lamp according to claim 17, wherein a separation rib is disposed between said placement flange and said abutment flange, wherein the separation rib protrudes substantially perpendicular from said cover plate holder, and wherein the separation rib extends into said housing interior when the cover plate holder is coupled to the lamp housing.

20. The explosion-proof lamp according to claim 19, characterized in that a seal is disposed between said separation rib of said cover plate holder and said cover plate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Advantageous embodiments of the invention are further explained below in detail by use of the figures appended in the drawing,

(2) where:

(3) FIG. 1 shows a perspective view obliquely from below of a first embodiment of a lamp according to the invention;

(4) FIG. 2 shows a vertical sectional view through the lamp according to FIG. 1;

(5) FIG. 3 shows a perspective view obliquely from below onto a second embodiment of a lamp according to the invention, and

(6) FIG. 4 shows a vertical sectional view through the lamp according to FIG. 3.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

(7) FIG. 1 shows a perspective view obliquely from below onto a first embodiment of a lamp 1 according to the invention. It is substantially semi-cylindrical in shape with a respective semi-cylindrical casing 9 as part of lamp housing 2. On curved outer side 15 of lamp housing 2, a cooling device 6 is arranged in the form of a number of cooling fins 16 This cooling device 6 is formed in one piece with lamp housing 2. The respective cooling fins 16 extend over the entire length of lamp housing 2, see length 18, and in addition to having the same length, also have the same height 17, see FIG. 2.

(8) Respective cooling fins 16 are disposed spaced substantially equally from each other, where other devices can protrude from outer side 15 of lamp housing 2 between the cooling fins. Such devices are, for example, support flanges 22 that protrude outwardly at longitudinal ends 19 and 20 of lamp housing 2. Support flanges 22 are used to receive and mount fastening screws 23. They are used to fasten end cover plates 21 which cover respective openings on longitudinal ends 19, 20 of lamp housing 2 and have a substantially semicircular shape.

(9) At a highest point of lamp housing 2, see also FIG. 2, a fastening device 41 is further arranged between two adjacent cooling fins, by use of which the lamp housing can be fastened in a respective installation position.

(10) On an underside of lamp housing 2, a light outlet opening 5 is arranged which is in FIG. 1 partially covered by a cover plate holder 25. The latter comprises a support opening 26 which leaves a portion of light outlet opening 5 exposed. A cover plate 11 is visible in the holder opening 26 and held in an explosion-proof manner by cover plate holder 25 on lamp housing 2.

(11) FIG. 2 shows a vertical sectional view through lamp 1 according to FIG. 1.

(12) The respective cooling device 6 in the embodiment illustrated comprises six cooling fins 16 of the same height 17 and the same length 18. They extend directly outwardly from outer side 15 of lamp housing 2. On an inner side 7 of lamp housing 2, a reflection device 4 is formed It can also be formed by a coating 8 which is applied directly to inner side 7 of lamp housing 2.

(13) Reflection device 4 can be applied to the entire inner side at least in the region of the respective semi-cylindrical casing 9. However, it is also possible that reflection device 4 is arranged only at locations of the inner side which are needed for reflection of light emitted from a light source 3 in the direction toward light outlet opening 5. In the embodiment illustrated, light sources 3 are arranged on either side of light outlet opening 5. Each of the light sources comprises a printed circuit board 13 or 14 with a plurality of LEDs 12 arranged thereon. The corresponding printed circuit board with LEDs can extend over the entire length of lamp housing 2.

(14) At least some of the light beams 39 are shown in FIG. 2 emitted from respective LEDs 12 and being reflected by reflection device 4 in the direction toward light outlet opening 5.

(15) Respective light sources 3 are arranged on bearing flanges 24, which are as part of lamp housing 2 disposed at the lower ends of semi-cylindrical casing 9 facing each other and defining light outlet opening 4. The respective bearing flanges 24 also extend substantially over the entire length of lamp housing 2.

(16) Bearing flanges 24 form longitudinal edges of light outlet opening 5, where cover plate holder 25 with separation ribs 29 protruding into the housing interior 38 is inserted into the light outlet opening. These separation ribs 29 extend substantially vertically relative to a placement flange 27 and an abutment flange 28 Placement flange 27 defines holder opening 26 on either side and cover plate 11 is placed on placement flange 27 from inside housing 38. Furthermore, a seal 30 is arranged between separation ribs 29 and lateral edges of cover plate 11.

(17) A similar connection between placement flange 27 and cover plate 11 is effected to provide a respective explosion protection of the ignition protection class Ex-d. A corresponding connection with this ignition protection class is also formed between abutment flange 28 bearing flange 24. It is at least for the connection between placement flange 27 and cover plate 11 also possible that adhesive bonding occurs there. In this case, cover plate holder 25 would together with cover plate 11 and seal 30 be a separately manageable component which is jointly attachable on lamp housing 2 by an appropriate connection between abutment flange 28 and bearing flange 24.

(18) To improve cooling, in particular of respective light sources 3, printed circuit board 13, 14 is usually in direct contact with bearing flange 24. However, it is also conceivable that a heat transfer layer is formed between the two, such as heat-conductive paste or the like.

(19) First heat dissipation from LEDs 12 can occur via the printed circuit board. There are a number of options for this. For example, special printed circuit board shapes can be used which exhibit particularly good thermal conductivity, such as printed circuit boards having a metal core. The heat of the LEDs can be passed, for example, to the metal core via a copper through-contact. The heat can then from the metal core be passed on directly to the lamp housing. Thermal conductivity can in this context be improved by heat-conductive paste or the like. Moreover, it is in this context of advantage if respective heat transfer is improved by mounting the printed circuit board without the surfaces to be joined being uneven and rough.

(20) It should at this stage be pointed out again that Ex-d or pressure-resistant enclosure is a type of ignition protection in which the components that can ignite an explosive atmosphere are disposed within a housing, for example, see FIGS. 1 and 3. This housing withstands an internal pressure which might arise during explosion of an explosive mixture within the housing. The housing is provided with respective gaps, for example, see a respective gap between bearing flange 24 and abutment flange 28. A respective gap can also be formed between cover plate 11 and placement flange 27, though adhesive bonding is in this case a connection option.

(21) FIG. 3 shows a perspective view obliquely from below onto a second embodiment of a lamp 1 according to the invention. It has a hemispherical shape with a corresponding hemispherical casing 10 as part of lamp housing 2. The diameter of the hemispherical casing 10 is in a lower end portion 40 somewhat enlarged in order to be able to there arrange the respective cover plate holder 25, see also FIG. 4.

(22) A cable feed-through fixture 42 protrudes laterally from lamp housing 2, through which a respective electrical power line can bin run in an explosion-proof manner into housing interior 38.

(23) Similar to lamp housing 2 of FIG. 2, a fastening device 41 is formed at the upper end of lamp housing 2 according to FIG. 4. Cooling device 6 is also in lamp housing 2 according to FIGS. 3 and 4 formed by lamp housing 2, where, however, outer side 15 of lamp housing 2 presently directly forms the respective cooling device 6.

(24) In analogy to the first embodiment, reflection device 4 is formed on an inner side 7 of lamp housing 2.

(25) Between lower end portion 40 and the remaining part of lamp housing 2, a stepped shoulder 37 is formed, see also FIG. 4, which together with an upper end 36 of an insertion flange 32 of cover plate holder 25 serves to clamp a respective printed circuit board 13, 14 with LEDs 12 as light source 3.

(26) Due to the specific shape of lamp housing 2 in the second embodiment, printed circuit board 13, 14 is designed as a fully circumferential printed circuit board ring 35. It is at its outer edge clamped in the manner described above.

(27) Respective LEDs 12 are arranged along printed circuit board ring 30 and a respective opening in printed circuit board ring 35 is associated with light outlet opening 5. It is encompassed by lower end portion 40.

(28) For arranging a respective cover plate 11 in the region of light outlet opening 5, a cover plate holder 25 is also used in the second embodiment. The latter in analogy to the first embodiment comprises a radially inwardly protruding placement flange 27, on which cover plate 11 is placeable from the top, i.e. from housing interior 38. In analogy to separation rib 29 according to the first embodiment, cover plate holder 25 on lateral outer ends 31 of placement flange 27 comprises insertion flange 32 that faces into housing interior 38. Disposed between the latter and cover plate 11 is a seal 30. A fastening ring 43 can additionally be provided, by which cover plate 1 is pushed in the direction toward placement flange 27 and held in abutment with placement flange 27.

(29) Insertion flange 32 is in an advantageous manner formed as a screw-in ring 33, where between the latter and in particular its outer side and an inner side of lower end portion 40 an Ex-d-thread 34 is formed. It is used for screwing screw-in ring 33 into lower end portion 40 of lamp housing 2 in a simple manner and at the same time for achieving a connection of the respective explosion protection class.

(30) The respective screw-in depth of screw-in ring 33 can be determined by edge flange 44 at the latter's lower end protruding outwardly, which in a screwed-in position of printed circuit board ring 35, see FIG. 4, abuts end portion 40 substantially from below.

(31) It has already been pointed out that an outer edge of printed circuit board ring 35 is clamped between upper end 36 of printed circuit board ring 35 and stepped shoulder 37, whereby printed circuit board ring 35 is fixed in its position.

(32) A connection between cover plate 11 and placement flange 27 can in a second embodiment be created, for example, by adhesive bonding.

(33) The lamp according to the invention has a simple and integrated arrangement of the reflection device and the cooling device. Reflection device 4 is in each case realized directly by a respective inner side 7 of lamp housing 2, where a coating 8 can additionally be applied to the inner side. Cooling device 6 is formed directly and in one piece by outer side 15 of lamp housing 2, where the outer side can for enhancing the cooling effect have respective cooling fins.

(34) Configuration of the lamp is according to the invention effected in an explosion-proof manner, for which purpose in particular a respective cover plate holder 25 is provided between which and in particular the cover plate a respective explosion-proof connection is realized. This can be done by a respective gap or by an adhesive bond. The respective type of explosion protection is also realized in that, for example, a respective fastening ring 43, see FIG. 4, is additionally used.

(35) Additional fastening elements, such as screws or the like, are also possible in order to fasten cover plate holder 25, for example, in the embodiment according to FIG. 2, to lamp housing 2.

(36) Furthermore, it is to be noted that cover plate holder 25, in addition to cooling by way of lamp housing 2, can assume a further cooling function, so that in particular dissipation of heat to the exterior can take place directly from the printed circuit board via cover plate holder 25. The respective cooling elements are formed from suitable materials, such as metals, thermally conductive plastic materials, ceramics or the like.

(37) It should also be noted that, for example, in the first embodiment according to FIGS. 1 and 2, the arrangement of the respective light source is effected directly via lamp housing. 2. In the second embodiment according to FIGS. 3 and 4, the arrangement and fixation is effected not only by the lamp housing, but in combination with screw-in ring 33 as part of cover plate holder 25.